title: Candidate genes that may be responsible for the unusual resistances exhibited by Bacillus pumilus SAFR-032 spores.
abstract: The spores of several Bacillus species, including Bacillus pumilus SAFR-032 and B. safensis FO-36b, which were isolated from the spacecraft assembly facility at NASA's Jet Propulsion Laboratory, are unusually resistant to UV radiation and hydrogen peroxide. In order to identify candidate genes that might be associated with these resistances, the whole genome of B. pumilus SAFR-032, and the draft genome of B. safensis FO-36b were compared in detail with the very closely related type strain B. pumilus ATCC7061(T). 170 genes are considered characteristic of SAFR-032, because they are absent from both FO-36b and ATCC7061(T). Forty of these SAFR-032 characteristic genes are entirely unique open reading frames. In addition, four genes are unique to the genomes of the resistant SAFR-032 and FO-36b. Fifty three genes involved in spore coat formation, regulation and germination, DNA repair, and peroxide resistance, are missing from all three genomes. The vast majority of these are cleanly deleted from their usual genomic context without any obvious replacement. Several DNA repair and peroxide resistance genes earlier reported to be unique to SAFR-032 are in fact shared with ATCC7061(T) and no longer considered to be promising candidates for association with the elevated resistances. Instead, several SAFR-032 characteristic genes were identified, which along with one or more of the unique SAFR-032 genes may be responsible for the elevated resistances. These new candidates include five genes associated with DNA repair, namely, BPUM_0608 a helicase, BPUM_0652 an ATP binding protein, BPUM_0653 an endonuclease, BPUM_0656 a DNA cytosine-5- methyltransferase, and BPUM_3674 a DNA helicase. Three of these candidate genes are in immediate proximity of two conserved hypothetical proteins, BPUM_0654 and BPUM_0655 that are also absent from both FO-36b and ATCC7061(T). This cluster of five genes is considered to be an especially promising target for future experimental work.
authors.affiliation: Department of Biology and Biochemistry, University of Houston, Houston, Texas, United States of America.
authors.forename: Madhan R
authors.initials: MR
authors.lastname: Tirumalai
authors.forename: Rajat
authors.initials: R
authors.lastname: Rastogi
authors.forename: Nader
authors.initials: N
authors.lastname: Zamani
authors.forename: Elisha
authors.initials: E
authors.lastname: O'Bryant Williams
authors.forename: Shamail
authors.initials: S
authors.lastname: Allen
authors.forename: Fatma
authors.initials: F
authors.lastname: Diouf
authors.forename: Sharon
authors.initials: S
authors.lastname: Kwende
authors.forename: George M
authors.initials: GM
authors.lastname: Weinstock
authors.forename: Kasthuri J
authors.initials: KJ
authors.lastname: Venkateswaran
authors.forename: George E
authors.initials: GE
authors.lastname: Fox
mesh_terms: D001407:Bacillus / Q000235:genetics* / Q000502:physiology; D001426:Bacterial Proteins / Q000235:genetics; D005798:Genes, Bacterial; D056726:Genetic Association Studies; D050296:Microbial Viability / Q000235:genetics* / Q000528:radiation effects; D058977:Molecular Sequence Annotation; D011544:Pseudogenes; D017422:Sequence Analysis, DNA; D018531:Spacecraft; D013171:Spores, Bacterial / Q000235:genetics; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins